What Is a Security Number on a Credit Card?

A credit card security number serves as a protective measure against unauthorized transactions. This unique code helps verify that the person using the card during a purchase is the legitimate cardholder. It adds an important layer of security, especially when the physical card is not present, such as during online shopping or phone orders.

Understanding the Card Security Number

The card security number is a series of digits printed on a credit or debit card, designed to confirm physical possession during card-not-present transactions. While its purpose remains consistent, this security feature is known by several names depending on the card network. Visa typically refers to it as the Card Verification Value (CVV), while Mastercard uses the term Card Verification Code (CVC). Discover and American Express often call it the Card Identification Number (CID), though American Express also uses Card Security Code (CSC), and some sources refer to it generally as a Card Code Verification (CCV).

Locating Your Card Security Number

The location and number of digits for your card security number vary by card issuer. For Visa, Mastercard, and Discover cards, a three-digit number is typically found on the back, in or near the signature strip area. American Express cards feature a four-digit security number on the front, usually printed above the primary account number.

The Role of the Card Security Number in Security

This security number enhances transaction security by providing a verification method that is not easily compromised. Unlike the embossed card number, the security code is printed flat and is not encoded in the card’s magnetic stripe or embedded in the EMV chip data. This design makes it difficult for fraudsters to capture the code through skimming devices or other traditional card theft methods. Its primary role is to prevent fraud in “card-not-present” transactions, such as online or telephone purchases, by ensuring the individual has the physical card in their possession. Payment industry standards prohibit merchants from storing this number after authorization, minimizing exposure risk during data breaches.

Safeguarding Your Card Security Number

Protecting your card security number is straightforward and involves several simple practices. You should avoid sharing this number with anyone unless it is for a legitimate transaction with a trusted merchant. When making online purchases, always ensure the website is secure by looking for “https://” in the web address and a padlock icon in your browser’s address bar before entering any card details. Be cautious of unsolicited requests for your security number, whether by email, phone, or text message, as these are common tactics used in phishing scams. Legitimate organizations typically do not request this information outside of a secure payment portal.